Consider the House as a Whole for Energy Efficiency
By Bill Primavera
The Home Guru
Don’t the winters seem to be getting more severe each year? And with the lower temperatures, we’re all thinking about how well or how poorly our houses are insulated.
Just the other day, when meeting with a landlord in front of a house I was seeking to rent for her, she looked up at the roof, then looked at other roofs on the same street and said, “I can always tell how well my neighbor’s roofs are insulated by the amount of snow on them.”
I’m hoping that she doesn’t pass by my house because the secret will be out that my attic is not insulated between the rafters. In an 18th century structure with wooden peg construction and hand hewn beams, the attic is an open display of the brilliant work of carpenters long ago. If I were to place panels of insulation between the rafters, I’d ruin the look that I love. Let the next owner do it, I say.
However, I wasn’t totally negligent. I did insulate heavily under the attic flooring and placed a collection of rugs on top of it. Further, I insulated the back of the antique door leading to the attic steps.
Considering how long ago the communities in our area were built up, I think it’s reasonable to assume that most of us live in older homes rather than newer ones. And since the 50s and 60s when major tracks of housing were built here, the technology of insulation has been greatly advanced. Some of us have upgraded and others have not, so our homes all have varying degrees of energy efficiency.
New products are always being created that improve energy loss and gain readings. For instance, at a home show in the fall, I discovered a relatively new product called eShield Attic Energy Barrier that looks like the silvery material used on space suits. And, indeed, I learned that it features the same radiant barrier technology used in space and can cut heating and cooling bills by 25 percent or more.
To learn more about it, I called Mark Sackerson, an energy consultant with Franzoso Energy Solutions which represents the product. When we met, I was cautioned that properly insulating a house is a more complex proposition than installing a single new product.
“Better insulation techniques involve evaluating the house as a whole system,” Sackerson said, “and that means looking at three types of energy gain and loss. We must consider conduction, which is what happens when two materials are in contact; convection, which pertains to air circulation; and radiation, which is when an object gives off heat and it radiates out.
“Today there is a new focus on energy saving methods that rely on testing and quantifying the air exchange a house has, identifying the air leaks that can be stopped, and improving the thermal boundary, meaning the insulation,” he added.
A major consideration in the process is the need for a certain amount of air exchange between the inside and outside for a healthy environment. Sackerson noted that at one time in the 70s, some installers were wrapping a house in materials that failed to allow for the interchange of air, trapping moisture inside which in turn led to mildew and mold problems.
What usually doesn’t get addressed, according to Sackerson, is radiant heat gain and loss, especially in the attic. Today that problem is addressed with as much attention as the big movement in the 1980s toward window insulation that all but eliminated the heat radiating out by creating an air space between panes, the best kind of insulator.
The eShield product, which essentially is two sheets of aluminum with a layer of fiberglass between them, is one that addresses radiant heat gain and loss in the attic space.
The product is not sold directly to the consumer because the manufacturer insists that it be installed properly for maximum effectiveness, working in concert with the other insulation methods of the house. Also, there could be a danger where a homeowner might think that if it’s good to use this product between the rafters, it would be even better to use it also on the walls and floors, but that is not necessarily the case. That might create a complete envelope of the attic, trapping moisture and creating mold and mildew problems.
“For a healthy environment, you don’t want to tighten your house too much,” Sackerson said. “Again, insulation must be approached as a whole system. If you come in and insulate but don’t air seal, or if you create a thermal boundary without a pressure boundary, then at best you’ve addressed only half the issue. So, it’s not a simple matter of just installing a new insulating material.”
My lesson for the day was that a house must be considered as a living, breathing whole in seeking to achieve optimal energy efficiency and an overall healthy environment. And, that is best left to a professional energy consultant as a sort of house doctor.
For more information about energy efficiency, Mark Sackerson can be reached at 914-271-4572.
Bill Primavera is a licensed Realtor® (www.PrimaveraHomes.com), affiliated with Coldwell Banker, and a marketing practitioner (www.PrimaveraPR.com). For questions or comments about the housing market, or selling or buying a home, he can be reached directly at 914-522-2076.